Process for controlling the combustion of fuel.



UNITED STATES PATENT OFFICE.

HENRY .I. WILLIAMS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE COAL TREATING COMPANY, OF PHCENIX, ARIZONA TERRITORY, AND BOSTON, MASSACHUSETTS, A

CORPORATION OF ARIZONA TERRITORY.

PROCESS FOR CONTROLLING THE COMBUSTION OF FUEL.

To all whom it may concern:

Be it known that I, HENRY J. WILLIAMS, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Processes for Controlling the Combustion of Fuel and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to a process for controlling the combustion of fuel, and has for its object the provision of a cheap and certain method for facilitating the combustion of coal and at the same time preventing the production of smoke.

In the application of Newell W. Bloss, Se-

rial No. 433,234, filed May 16, 1908, there is disclosed a process for accomplishing the above purposes wherein catalytic agents are used, and especially salts of the alkali group in thin films; sodium nitrate being preferred. And in my other pending application No. 437,721, filed June 10, 1908, I have disclosed a process for controlling the combustion of fuel and for preventing smoke which employs thin films of salts of the alkaline earths, especiall those of calcium. From a series of furt er experiments carried on by myself, I

ing the fuel, preferably coal, with a thin film of a salt of these metals, then igniting the fuel and permitting it to generate a combustible gas, which in turn ignites and produces a flame much longer than is produced under the same conditions when the fuel is not so treated.

'In carrying out my process I preferably.

employ a salt which is soluble in water, and coat the fuel with a water solution of the same by either a sprinkling or adipping process, preferably the latter. After the coal, or other fuel, is thoroughly coated with this solution and allowed to drain, it is then placed upon a fire kindled in the ordinary way. As

Specification of Letters Patent.

Application filed June 22, 1908.

Patented Aug. 25, 1908.

Serial No. 439,853.

soon as the water is driven off and a temperature of about 1000 F. in the fire is reached, blue flames begin to appear which at first gradually increase, and then rapidly grow longer as the temperature rises, until at a temperature in the neighborhood of 1800 E, there exist flames very greatly exceeding in volume and length any flames that could be produced under like conditions if the coal were not coated with one of the solutions mentioned, or its equivalent.

In some trials recently made by me, the coal used was the well kllOWll graphitic Rhode Island coal which is so difficult to ignite; and I used in successive trials solutions of ferric chlorid, Fe,Cl,,, of manganous chlorid, MnCl,, and ammonio cupric chlorid, CuCl 2(NI-ICl) 2H,,O. The proportion of salt used in each case for each solution was one part of salt to twenty parts of water. In each case there occurred a vivid livening of the fire with a development of flames many times longer than could be produced under like conditions with the un treated coal, and these flames were observed for a considerable length of time, say 40 minutes in each case; and they undoubtedly would have been observed for longer times had the conditions of the trials permitted. In each case, also, the treated red hot lumps, when removed from the fire, showed a zone of blue flame emitted from each lump, and visible over its whole surface. tests of the action of solutions of chromic acid, CrO and aluminic chlorid Al Cl with the above Rhode Island coal, and found these salts to act in the same general way as the above, both in producing longer flames than was possible with the untreated coal under like conditions, and in roducing a zone of blue flame around the ignited surfaces of the red hot lumps. The only rational explanation of this remarkable action, exemplified in these tests, as well as the tests set forth in the applications above, to my mind, is to be found in one or more of the theories of catalytic action. In brief, it seems certain to me that each of the salts above, are in the presence of air and at the high temperatures to which they are subjected, converted into an oxid of the metal, and this oxid is continually reduced by the red hot carbon on one side of the thin film coating the coal, and continually reformed by the oxygen of the I, also, made Cir air on the other side; while the carbon monoXid thus formed by the reduction leaves the system to be further ignited beyond the region of the red hot coal. Of course, this reduction of the metallic oXids Will only take place above a certain temperature, and unless the fire is kept at this temperature the catalytic action will cease. It is evident that every portion of all the surfaces of all the lumps cannot be expected to be coated with a thin film of oXid and it seems entirely reasonable that any portions not so coated should receive more oxygen from the air, and burn to carbon di-oxid, CO and therefore liberate sufficient heat to keep the temperature up to the point necessaryto bring into play the catalytic actions above mentioned. Of course, it would follow from such a theory that some salts would act better as catalyzers than others; and such is confirmed by experiment; for some of the salts in the tests above mentioned seemed to produce better results than others. It is, also, possible that the oXids of those metals which form fusible silicates with the greatest difiiculty are the ones which are the most likely to remain in the furnace the longest time, as Well as to be the most active in producing CO gas; for the reason that oXids which would form fusible slags in the presence of red 'hot carbon, of course, would not so readily suffer reduction and thereby produce carbon monoxid; and furthermore, such slags would be sure to collect through the action of their own high surface tension, into films on the fuel too thick to act catalytically. It seems evident, therefore, that salts of copper, iron, aluminum, chromium, manganese, nickel, cobalt, tin, gold and platinum, would act qualitatively the same.

My present invention. accordingly comprises the application to the fuel of thin films from solutions of the salts of those regular metals which are characterized by the fact, that under ordinary furnace temperatures, they will remain in the furnace without substantial volatilization; and which are of such a nature that they will not readily become inactive catalytically through permanent ifluXing with impurities in the fuel, at the ordinary temperatures of furnaces.

Of course, I do not limit myself to the catalytic theory, nor to anyparticular theory, for the reason that the chemistry of these re markable results, as Well as the whole chemistry relating to the reactions that actually take place in a furnace, is so little understood at the present time but nevertheless,

I believe one or more of the catalytic theories to be found in the more advanced.modern chemistries constitute the only rational 0X.- planation of these results that at present is known.

What I claim is 1. The process of facilitating the co1nbustion of fuel, which consists in coating the same with a thin film from a solution of a salt of a metal practically non-volatilizable in the furnace; then igniting said fuel and permitting said film, when the fuel is burned, to cause carbon to be withdrawn from said fuel and to be set free in the form of a combustible gas, substantially as described.

2. The process of facilitating the combustion of fuel, which consists in coating the same with a solution of a salt of a metal practically non-volatilizable in the furnace; igniting said fuel 'andpermitting the film thus formed to act catalytically to cause carbon to be withdrawn from said fuel and set free in the form of a combustible gas, substantially as described.

3. The process of facilitating the combustion of fuel, which consists in coatin said fuel with a thin film from a solution of a sa t of a metal, which film at the ordinary i(ll\- peratures of the furnace in the presei'iee of carbon is practically non-volatilizal)le, nor readily form a fusible slag with the impurities of the fuel; allowing said. fuel to drain. and then igniting said fuel, sul)stantiall as described. a

4. The process of facilitating the combustion of fuel, which consists in treating said fuel with a dilute water solution of a salt of the copper-iron group of metals, leaving thereon a thin film, and then igniting said fuel, substantially as described.

5. The process of controlling the combustion of fuel, which consists in immersing said fuel in a dilute water solution of copper; draining said fuel and then igniting it, substantially as described.

6. The process of controlling the combustion of fuel, which consists in immersing the same in a solution of the proportions of about one part of copper salt to twenty parts of ater; allowing the fuel to drain and then igniting the same, substantially as described.

In testimony whereof, I aiIiX my signai;

ture, in presence of two witnesses.

HENRY J. WILLIAMS.

lVitnesses:

WARREN B. WHEELER, STILLMAN SHAW. 

